20840512349881 has 27 divisors (see below), whose sum is σ = 24398785943343. Its totient is φ = 17749268208000.

The previous prime is 20840512349863. The next prime is 20840512350019. The reversal of 20840512349881 is 18894321504802.

The square root of 20840512349881 is 4565141.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 835288151481 + 20005224198400 = 913941^2 + 4472720^2 .

It is not a de Polignac number, because 20840512349881 - 2³³ = 20831922415289 is a prime.

It is a super-2 number, since 2×20840512349881² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20840512349851) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5208823881 + ... + 5208827881.

Almost surely, 2^{20840512349881} is an apocalyptic number.

20840512349881 is the 4565141-st square number.

20840512349881 is the 2282571-st centered octagonal number.

It is an amenable number.

20840512349881 is a deficient number, since it is larger than the sum of its proper divisors (3558273593462).

20840512349881 is an frugal number, since it uses more digits than its factorization.

20840512349881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8342 (or 4171 counting only the distinct ones).

The product of its (nonzero) digits is 4423680, while the sum is 55.

The spelling of 20840512349881 in words is "twenty trillion, eight hundred forty billion, five hundred twelve million, three hundred forty-nine thousand, eight hundred eighty-one".